“I had one student who could do all the Āsana and was shocked to discover that she was unable to stay in Mahā Mudrā for eight breaths! She was so flexible that she took her body for granted.
Mahā Mudrā requires more than suppleness of the body.
We must be able to stay and breathe in this posture.”
– TKV Desikachar Religiousness in Yoga Chapter Four Page 45